time-to-botec/js/node_modules/@stdlib/ndarray/base/unary/README.md

Unary

Apply a unary callback to elements in a input ndarray and assign results to elements in an output ndarray.

Usage

var unary = require( '@stdlib/ndarray/base/unary' );

unary( arrays, fcn )

Applies a unary callback to elements in a input ndarray and assign results to elements in an output ndarray.

var Float64Array = require( '@stdlib/array/float64' );
var unary = require( '@stdlib/ndarray/base/unary' );

function scale( x ) {
    return x * 10.0;
}

// Create data buffers:
var arr = [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ];
var xbuf = new Float64Array( arr);
var ybuf = new Float64Array( 6 );

// Define the shape of the input and output arrays:
var shape = [ 3, 1, 2 ];

// Define the array strides:
var sx = [ 4, 4, 1 ];
var sy = [ 2, 2, 1 ];

// Define the index offsets:
var ox = 1;
var oy = 0;

// Create the input and output ndarray-like objects:
var x = {
    'dtype': 'float64',
    'data': xbuf,
    'shape': shape,
    'strides': sx,
    'offset': ox,
    'order': 'row-major'
};
var y = {
    'dtype': 'float64',
    'data': ybuf,
    'shape': shape,
    'strides': sy,
    'offset': oy,
    'order': 'row-major'
};

// Apply the unary function:
unary( [ x, y ], scale );

console.log( y.data );
// => <Float64Array>[ 20.0, 30.0, 60.0, 70.0, 100.0, 110.0 ]

Examples

var discreteUniform = require( '@stdlib/random/base/discrete-uniform' ).factory;
var filledarray = require( '@stdlib/array/filled' );
var gfillBy = require( '@stdlib/blas/ext/base/gfill-by' );
var shape2strides = require( '@stdlib/ndarray/base/shape2strides' );
var ndarray2array = require( '@stdlib/ndarray/base/to-array' );
var unary = require( '@stdlib/ndarray/base/unary' );

function scale( x ) {
    return x * 10;
}

var N = 10;

var xbuf = filledarray( 0, N, 'generic' );
gfillBy( xbuf.length, xbuf, 1, discreteUniform( -100, 100 ) );

var x = {
    'dtype': 'generic',
    'data': xbuf,
    'shape': [ 5, 2 ],
    'strides': [ 2, 1 ],
    'offset': 0,
    'order': 'row-major'
};
var y = {
    'dtype': 'generic',
    'data': filledarray( 0, N, 'generic' ),
    'shape': x.shape.slice(),
    'strides': shape2strides( x.shape, 'column-major' ),
    'offset': 0,
    'order': 'column-major'
};

unary( [ x, y ], scale );
console.log( ndarray2array( x.data, x.shape, x.strides, x.offset, x.order ) );
console.log( ndarray2array( y.data, y.shape, y.strides, y.offset, y.order ) );